[PATCH] coding-style: Add guidance to prefer dev_dbg

From: Abhishek Pandit-Subedi
Date: Thu Jan 25 2024 - 19:53:48 EST


During review, it was suggested that drivers only emit messages when
something is wrong or it is a debug message. Document this as a formal
recommendation.

https://lore.kernel.org/linux-usb/2024012525-alienate-frown-916b@gregkh/

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx>
---
I'm sending up the change to documentation while this is still fresh.
Will send an update to checkpatch.pl afterwards.

Documentation/process/coding-style.rst | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/process/coding-style.rst b/Documentation/process/coding-style.rst
index c48382c6b477..f8ec23fa89bc 100644
--- a/Documentation/process/coding-style.rst
+++ b/Documentation/process/coding-style.rst
@@ -899,7 +899,8 @@ which you should use to make sure messages are matched to the right device
and driver, and are tagged with the right level: dev_err(), dev_warn(),
dev_info(), and so forth. For messages that aren't associated with a
particular device, <linux/printk.h> defines pr_notice(), pr_info(),
-pr_warn(), pr_err(), etc.
+pr_warn(), pr_err(), etc. When drivers are working properly they are quiet,
+so prefer to use dev_dbg/pr_debug unless something is wrong.

Coming up with good debugging messages can be quite a challenge; and once
you have them, they can be a huge help for remote troubleshooting. However
--
2.43.0.429.g432eaa2c6b-goog